Policy Groups: A New Approach to Linux Memory Management
LAS VEGAS, NV – June 15, 2026 – A controversial proposal to overhaul Linux memory management emerged Tuesday at the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit. Kernel developer Chris Li unveiled 'policy groups,' a system designed to fill gaps left by the existing cgroup subsystem.
Li, speaking at the memory-management track, declared that control groups 'work well for resource management' but 'fail for policy-driven use cases.' The proposed enhancement aims to decouple policy enforcement from resource limits.
While Li’s session drew significant interest, a clear path to consensus remains elusive. Multiple developers raised concerns about implementation complexity and potential overlaps with existing features.
What Are Policy Groups?
Policy groups extend the kernel's ability to enforce access controls, priority rules, and custom memory policies—without being tied to traditional resource accounting. Li explained, 'We need a mechanism that allows administrators to say: this group of processes gets preferential treatment, not just a fixed allocation.'
The idea emerged from Li's work on embedded systems and cloud-native environments where control groups impose rigidity. 'In practice, admins often override cgroup limits with hacks,' Li noted. 'Policy groups would make this official and safe.'
A prototype presented at the summit showed policy groups intercepting memory allocation calls and applying per-packet rules, achieving near-zero overhead. However, critics warned that adding another layer could increase kernel complexity.
Background: The Control Group Debate
Control groups (cgroups) have been part of the Linux kernel since 2007, primarily for resource usage limits (CPU, memory, I/O). They form the basis of container technologies like Docker and Kubernetes. But their design focuses on isolation, not flexible policy enforcement.
Li’s policy groups propose to address three pain points:
- No override mechanism – Admins cannot easily grant temporary priority boosts without changing cgroup weights.
- Tied to hierarchy – Policies cannot cross cgroup boundaries.
- No fine-grained memory controls – E.g., marking specific memory regions as 'fast' or 'protected' is not possible.
Previous attempts (such as memory policy in cgroup v2) were met with limited adoption. Li believes policy groups can succeed by being completely opt-in and backward-compatible.
What This Means for Linux
If implemented, policy groups could transform how cloud providers and enterprise users manage memory. For instance, a database process could receive guaranteed high-priority access to a specific NUMA node, while other processes remain unaware.
Security-wise, policy groups might tighten kernel hardening by preventing out-of-bounds memory access based on process identity. However, integration with existing security modules (SELinux, AppArmor) is still an open question.
Despite the promise, the Linux kernel community is known for its slow adoption of big changes. 'This is a 5-year effort, not 5 months,' cautioned veteran kernel maintainer Greg Kroah-Hartman. Li acknowledged the timetable, but urged early prototyping: 'We don’t need consensus now; we need experiments to validate the concept.'
The summit's outcome was inconclusive. An ad-hoc working group was formed to draft a formal RFC by October, with design decisions tracked in a public repository. Developers can expect heated discussions on mailing lists in the coming weeks.
Expert Reactions
'Policy groups address a real need in high-performance computing where custom memory placement is critical,' said Dr. Maria Santos, a kernel researcher at Red Hat. 'But we must ensure it doesn't become another dead code path.'
Li remains optimistic. 'The kernel has evolved by adding new abstractions, not by perfecting old ones. Policy groups are the next step.'